The use of ladders, extensions, and scaffolding to reach objects extending above the height of an individual is as old as antiquity itself. The ladder arts are filled with many variations of extension assemblies. Many ladder assemblies illustrate fold-up ladders and ladders having fold-away steps.
In U.S. Pat. No. 4,757,876, issued to Peacock, on Jul. 19, 1988, for FOLDABLE TAIL GATE STEP ASSEMBLY, a small, fold-up ladder assembly is shown. The small ladder is intended to be used as a mounting platform at the back, or tail gate, of a truck or other vehicle. The ladder is foldable about its mid-section, and has fold-away steps. The steps individually fold away into the frame by means of a slot and pin arrangement. The pin is carried at the end portion of the step and rides within the slot of an extension member as the step is caused to be folded into the frame.
In U.S. Pat. No. 2,596,521, issued to Bell, on May 13, 1952 for STEPLADDER, a small stepladder is shown, wherein all the steps of the ladder are folded away simultaneously when the frame of the ladder is folded down. In its folded state, all of the steps project slightly above the frame surface.
A small step ladder, called Little Jumbo, featuring foldable steps and frame, is sold by Wing Enterprises, Inc. of Springville, Utah. This ladder has steps that simultaneously fold into the frame when the frame is collapsed, similar to the aforementioned ladder described by Bell.
The present invention features a full-length step ladder whose steps individually fold away into the frame. The invention differs from the previously described ladders in several important ways:
(a) the step ladder of this invention has steps that individually fold below the frame. This is a very useful feature when climbing the ladder, since a person can lean into the frame and obtain added reach to a wall or adjacent work surface without discomforting or injuring his or her shins; PA1 (b) the sides of each step are rotationally anchored to the middle of the frame, so that the steps are indented to the frame in the fold-away position and do not project beyond the frame surface in the step operative position. This feature is very useful in providing a smooth, lean profile. The indenting of the steps also allows one to step or lean further into the ladder, thus providing safer footing and a longer reach towards an adjoining vertical work surface; PA1 (c) each step is braced in its extended position by a right-angled flange. These flange braces provide greater internal support for the steps, so that the steps can be designed larger than normal steps of a step ladder. The larger steps provide better support and thus, less fatigue, than do conventional step ladder rungs; and they also provide a feeling of sure-footed stepping when one places a foot thereupon; PA1 (d) unlike its predecessors, the ladder of this invention is full-sized. Prior art ladders of the folding step variety usually extend or rise only a few feet from the ground. This limitation is owing to the outwardly-projecting, fold-away steps which interfere with each other. By contrast, the ladder of the present invention has inwardly-projecting and recessed steps that allow the ladder to be built with full-length extension or height and no step interference for the worker's shins.